The following U.S. Patents are incorporated herein by reference, in entirety:
U.S. Pat. No. 4,893,591 discloses a flame arrestor system for use with an internal combustion engine having a plurality of cylinders. Each cylinder has an intake port and means of ignition of combustible mixtures drawn into the cylinder through the intake port, and an intake manifold connecting the intake ports of a plurality of cylinders. The system serves to reduce the possibility of transmission of combustion producing flame from a cylinder into the intake manifold comprising a flame arrestor positioned between the intake manifold and each cylinder intake port. Each flame arrestor permits passage of combustible mixtures therethrough but prohibits the passage of flame therethrough.
U.S. Pat. No. 5,357,913 discloses a pair of embodiments of flame arrester arrangements for marine propulsion engines wherein the flame arrester is positioned vertically above the thermostat housing at one end of the engine and the plenum chamber for the intake manifold is disposed above the exhaust elbow of the engine so as to provide good induction efficiency and compact size.